I think sooner the better with this also, the longer it drags out and other people talk to her the messier it may end up. If she also seeks legal advice they might find she's entitles to more than the $7300.
So best to act quickly!
Go see a Family law lawyer ASAP.
If you can get a Binding Financial Agreement written up and only have to pay her $7300 you've basically won the lotto.
I think the costs for a BFA are around $1000-2000. Will let the lawyers comment more.